Study On The Durability Of CRTSⅢ Ballastless Slab Track

With the development of high-speed railway in China, ballastless track has been widely used due to its excellent stability, less maintenance workload and long service life. CRTSIII ballastless slab track, applied to Chengdu-Dujiangyan Fast Railway, gives a new direction for the research and design of ballastless track. The service life of ballastless track demands for60years which requires the estimate and analysis of durability while tracks are being designed.Based on the CRTS III ballastless slab track, a coupling static model is established for the factors research of ballastless track durability. The main research contents are as follows:1.Building two static models of CRTS III ballastless slab track with single groove and two grooves by the FEA software ABAQUS separately. Based on the stress results of concrete and steel bars, this paper calculates the maximum crack width and fatigue of track structures, and according to S-N curve of concrete and steel, forecasts the fatigue life of ballastless track. The analyses and calculations show that track with two grooves is better than track with only one groove considering durability due to the good results of checking of crack width and fatigue and the results of fatigue life forecasts.2.Building FEA models of reinforced concrete with insulation bands and epoxy resin coated steel bars embedded in it and analyzing the mechanical properties of FEA models with loads applied. Because the reinforced concrete with insulation bands is easy to cause stress concentration and cracks around the insulation bands, taking durability into account, we recommend to use FERCS for reinforced insulation.3.Building durability calculation model of ballastless track in terms of holism. Analyzing the structure durability and environment actions of CRTSIII ballastless slab track which are located on north region, central region and south region and estimating the track structure durability status. After calculation, we concluded that track in northern area should increase its track thickness and reinforcements along its service life will increase the structure durability.